Stethoscopes have long been used by physicians to monitor auscultatory sounds. Typically stethoscopes have been comprised of a head or chestpiece, a sound transmission mechanism and an earpiece assembly. The chestpiece is adapted to be placed near or against the skin, body, of a patient for gathering the auscultatory sounds. The sound transmission mechanism transmits the gathered sound to an earpiece, or a pair of earpieces called a binaural earpiece, where the physician or other health professional may monitor the sound.
Recently, some stethoscopes have utilized electronics for at least part of the sound processing path. In most of these devices, the auditory sound is picked up by a microphone usually located in a detection device which is similar to the chestpiece of a conventional acoustic stethoscope in external appearance. The electrical signal from the microphone is then processed electronically and is coupled to a speaker, or speakers, where the electrical signal is converted back into an auditory sound for reception by the physician. Of course, other electronic analysis or display of the auscultatory sound may be performed by the signal processor, in addition to the usual conversion back into an auditory sound.
The incorporation of electronic circuitry into the stethoscope has been a considerable design problem for the engineer. Electronic circuitry necessarily demands a supply of energy, most commonly a battery. Typically the batteries used in electronic stethoscopes have been of the small high energy density power cells such as those used in hearing aids, or selectively chosen and/or multiple units of more standard power cells that are operated within limited life cycles. Unfortunately, these specialized batteries are not widely available and are often expensive and difficult to dispose of.
In addition, although an electronic stethoscope allows for the provision of many desirable features, such as noise reduction, signal amplification, wider bandwidth, display of auscultatory sounds and selection of different frequency responses, the electronic scope has not gained wide acceptance due to the impression that electronic stethoscopes sound "different" or "electronic" or in some way distort the sound. Given that health care practitioners have long performed auscultation and based diagnosis on the sounds heard through a traditional acoustic stethoscope, the reluctance to change to something that sounds "different" is understandable.
Thus, there is a need in the art for an electronic stethoscope which sounds more like the traditional acoustic stethoscope but which has the additional desirable features which only an electronic stethoscope can provide.